after i finished the storyline of GOF i was curious. I especially had a look at the systems.bin file with a hex-editor in the data/bin-folder of the game and for my surprise there are already some systems configured (same in stations.bin - there is a hint for the very interesting Shima station - Kaamo Club) that you can not jump to. They are part of some add-on. If you have a look at the map you will see a few stars that are not active AFAIK. Or did i miss something and the system are unlockable in some way after the storyline-ending?

In the systems.bin you can find the names and other stuff for the systems. I already figured out how to change the faction, star-type (green, yellow,...), the coordinates where they are placed on the map and the security status. but no way at the moment how to unlock them for the player.

stuff i found already for example the wolf-reiser system (a little bit formated):

The Kaamo Club-Shima as well as several other systems are a part of two other DLC's. I own GOF 1 & 2 for my iPhone, loved them both. GOF 2 has 2 major addons, "Valkryie" and "Supernova". Both add Storylines, features, weapons, ships, and systems. The Kaamo Club/Shima system was part of the "Kaamo Club" addon, which initialy just gave you a space station to store stuff as well as extra ships, but as of the "Supernova" expansion, it has vendors in the bar that sell ships, ship upgrades, and random high end weapons. Whether or not you can unlock all or any of this content would be interesting, but unless all of the content for the addons came already built in, I doubt it. The storyline picks up in "Valkryie" and then in "Supernova" full voice acting and everything. I really hope they release these expansions as it not only adds hours of storyline gameplay, but very much improves on a already great game.